It is known in practice to conduct a transmission inspection for controlling the quality of container glasses. This inspection is done by means of a camera which is directed through the opening of the container glass onto a diffuse illumination arranged below the bottom. The resulting camera image can be evaluated using electronic image processing or visual inspection by operators to thus detect contaminations, cracks or irregularities of form.
The drawback of such known systems is that the inspection work can only be accomplished inadequately when the bottoms have complex shapes. For example, the bottoms of container glasses are often provided with structural elements which can cause false-positive or false-negative inspection results when tested for contaminations.
Proceeding from this prior art, it is an object of the invention to provide an apparatus and a method for controlling the quality of transparent objects, the reliability of which is increased.